import pygame
pygame.init()
scr = pygame.display.set_mode([640, 480])
scr.fill([0, 0, 0])
x, y = 300, 210
pygame.draw.circle(scr, [255, 0, 0], [x, y], 40, 0)
pygame.display.flip()
running = True
while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False
        elif event.type == pygame.KEYDOWN:
            if event.key == pygame.K_a:
                scr.fill([0, 0, 0])
                x = x - 10
                pygame.draw.circle(scr, [255, 0, 0], [x, y], 40, 0)
                pygame.display.flip()
            elif event.key == pygame.K_d:
                scr.fill([0, 0, 0])
                x = x + 10
                pygame.draw.circle(scr, [255, 0, 0], [x, y], 40, 0)
                pygame.display.flip()
            elif event.key == pygame.K_w:
                scr.fill([0, 0, 0])
                y = y - 10
                pygame.draw.circle(scr, [255, 0, 0], [x, y], 40, 0)
                pygame.display.flip()
            elif event.key == pygame.K_s:
                scr.fill([0, 0, 0])
                y = y + 10
                pygame.draw.circle(scr, [255, 0, 0], [x, y], 40, 0)
                pygame.display.flip()
pygame.quit()